Jack stands are essential safety equipment for anyone who needs to work underneath a car, truck, or SUV. A hydraulic jack alone is never enough to support a vehicle safely during maintenance or repairs, and improper use of jack stands causes serious injuries and deaths every year.
This guide explains how to select the right jack stands, where to position them on your vehicle, and how to use them correctly so you can work safely beneath your car or truck.
What Are Jack Stands and How Do You Use Them Safely?
Jack stands are adjustable metal supports designed to hold a vehicle at a fixed height after it has been raised with a jack. You position them under designated support points on the vehicle’s frame or chassis, lower the vehicle onto them, and leave the stands in place while you work underneath. Never rely on a hydraulic or scissor jack alone to support a vehicle during any repair or maintenance task.
Why Jack Stands Are Required for Underneath Work
Hydraulic jacks can fail without warning due to seal leaks, air in the system, or accidental release of the valve. Scissor jacks supplied with vehicles are designed only for roadside tire changes and can tip or collapse under side loads.
Jack stands provide a solid, stable support that does not rely on hydraulic pressure or mechanical advantage. They distribute the vehicle’s weight across a wider base and lock at a fixed height, eliminating the risk of sudden collapse that makes working under a jack-supported vehicle extremely dangerous.
Choosing the Right Jack Stands
Jack stands are rated by weight capacity per pair, typically ranging from 3 tons to 6 tons or more. You must select stands rated to support the full weight of your vehicle with a safety margin.
Capacity Requirements
Check your vehicle’s curb weight in the owner’s manual or on the driver’s door jamb label. Choose jack stands rated for at least the full curb weight even if you plan to lift only one end of the vehicle, because uneven loading and dynamic forces require extra capacity.
A compact sedan weighing 3,000 pounds requires at least 3-ton stands, while a full-size truck or SUV weighing 6,000 pounds or more needs 6-ton stands. Heavier vehicles such as large trucks and some electric vehicles with heavy battery packs may require commercial-grade stands with even higher ratings.
Stand Design and Construction
Quality jack stands feature a wide, stable base, a strong vertical support column, and a secure locking mechanism. Look for stands with multiple height adjustment positions using pins or ratcheting teeth rather than friction alone.
The saddle or top surface should be large enough to contact the vehicle’s support point fully and may include rubber padding to prevent metal-to-metal contact. Avoid stands with bent components, cracked welds, stripped threads, or missing pins, as these defects compromise safety.
Where to Position Jack Stands on Your Vehicle
Every vehicle has specific jacking and support points engineered to handle lifting loads safely. Using the wrong locations can damage the vehicle or cause it to slip off the stands.
Locating Factory Support Points
Consult your owner’s manual for the exact locations of approved jacking and support points for your specific make, model, and year. Common support points include reinforced sections of the frame rails, pinch welds along the rocker panels, subframe members, and rear axle housings on solid-axle vehicles.
Look for factory markings, notches, or reinforced areas that indicate proper support locations. Never position stands under body panels, suspension components, the oil pan, transmission housing, or other parts not designed to bear the vehicle’s full weight.
Front and Rear Support Differences
Front support points are typically located on the frame rails or subframe behind the front wheels. Some vehicles use pinch weld locations on the rocker panels, which require adapters or saddles shaped to fit the pinch weld profile.
Rear support points may be on the frame rails, rear axle housing, or dedicated lift points depending on whether the vehicle has independent or solid rear suspension. Verify the correct locations in your service information, as incorrect placement can bend suspension components or puncture fuel tanks and brake lines.
Preparing to Use Jack Stands Safely
Proper preparation prevents accidents and ensures stable support throughout your work session. Never skip safety steps to save time.
Selecting a Work Surface
Always work on a firm, level surface such as a concrete driveway or garage floor. Asphalt, dirt, gravel, grass, and sloped surfaces allow jacks and stands to sink, shift, or tip.
If you must work on a slight incline, position the vehicle so it cannot roll forward or backward and use additional wheel chocks. Avoid working outdoors in high wind, rain, or icy conditions that can affect stability.
Using Wheel Chocks
Place wheel chocks on both sides of at least one wheel that will remain on the ground. If you are lifting the front of the vehicle, chock the rear wheels, and vice versa.
Commercial rubber or metal chocks are more reliable than bricks or wood blocks, which can crumble or slip. Position chocks tightly against the tire tread to prevent any movement before you begin lifting.
Engaging the Parking Brake
Set the parking brake before lifting the vehicle, even when using wheel chocks. If you need to lift the rear wheels on a vehicle with rear-wheel parking brakes, the parking brake effectiveness will be reduced, making front wheel chocks especially important.
On vehicles with electronic parking brakes that release when the ignition is turned on, consider leaving the ignition off and transmission in Park or first gear as an additional precaution.
Step-by-Step Instructions for Using Jack Stands
Follow this sequence every time you use jack stands to ensure maximum safety and stability.
- Position the hydraulic or floor jack under the vehicle’s designated jacking point closest to where you will place the first jack stand. Consult your owner’s manual to confirm the correct jacking point for lifting the vehicle initially.
- Raise the vehicle slowly with the jack until the tire just clears the ground or the chassis reaches the height you need for your work. Keep your body clear of the vehicle while lifting and watch for any shifting or instability.
- Position the first jack stand under the nearest designated support point. Adjust the height of the stand so the saddle will contact the support point firmly when the vehicle is lowered.
- Slowly lower the vehicle onto the jack stand by carefully releasing the jack valve. Allow the stand to take the full weight while keeping the jack in position as a backup.
- Repeat the process for the second jack stand on the opposite side of the vehicle. Raise that side with the jack, position the second stand under its support point, and lower the vehicle onto both stands.
- Check stability by gently pushing on the vehicle from several angles. The vehicle should sit solidly on both stands without rocking or shifting. If you detect any movement, raise the vehicle again and reposition the stands.
- Leave the jack in place as a backup support with some weight on it if possible, or position it nearby for quick use in an emergency. Never remove the jack and put it away while you are working under the vehicle.
- Verify stand engagement by visually confirming that the locking pins or ratchet teeth are fully engaged and that the saddles are centered on the support points with full contact.
Common Mistakes and How to Avoid Them
Seemingly minor errors in jack stand use can have serious consequences. Recognizing and avoiding these mistakes keeps you safe.
Lifting the Entire Vehicle with One Jack
Some procedures require lifting all four corners of a vehicle, but you cannot safely do this by placing a single jack under the center and then positioning four stands. This method creates instability and increases the risk that the vehicle will shift or fall.
Instead, lift one end of the vehicle at a time, secure it on two jack stands, then move to the opposite end. For mid-vehicle jacking points, lift one side completely before lifting the other.
Using Mismatched or Damaged Stands
Always use a matched pair of jack stands with the same height adjustment on both sides. Mismatched heights cause the vehicle to sit at an angle, which can overload one stand and create instability.
Inspect your stands before every use for cracks, bent components, missing pins, damaged threads, or rust that could compromise strength. Replace stands immediately if you find any defects.
Working Under an Unsupported Section
Even when the vehicle is properly supported on jack stands, avoid positioning your body directly under heavy components such as the engine, transmission, or rear axle unless those sections have additional support. Suspension settling, stand shifting, or component failure can cause localized collapse.
Use additional jack stands, a transmission jack, or a sturdy wooden beam to support heavy components you are removing or servicing. Never assume that two stands at the corners provide adequate support for every part of the vehicle.
Extending Stands Beyond Rated Capacity
Jack stands become less stable as you extend them to maximum height because the center of gravity rises and side-load resistance decreases. Whenever possible, use the lowest height adjustment that gives you adequate clearance for your work.
If you need more height than your stands can safely provide at their rated capacity, consider using larger stands, ramps in combination with stands, or a professional lift instead of extending smaller stands beyond their safe working range.
Lowering the Vehicle from Jack Stands
Removing jack stands safely requires the same care as positioning them. Position your hydraulic jack under the original jacking point and raise the vehicle just enough to unload the first jack stand, then remove that stand and repeat for the second.
Lower the vehicle slowly and evenly by releasing the jack valve in controlled increments. Keep your hands, feet, and body clear of the vehicle as it descends, and never reach under the vehicle until it is fully resting on its wheels with the jack removed.
When Professional Equipment Is Necessary
Some jobs require four-post lifts, two-post lifts, or transmission jacks that provide better access, stability, and weight distribution than jack stands. Major engine or transmission removal, exhaust system replacement, and extensive undercarriage work are safer and easier on professional equipment.
If you lack the proper support equipment for a job, the vehicle is too heavy for your stands, or you feel uncertain about any aspect of safely supporting the vehicle, take it to a professional shop with appropriate lifts and trained technicians. The cost of professional service is far less than the medical bills and vehicle damage that result from improper support.
Additional Safety Considerations
Never work alone under a vehicle in an isolated location. Having someone nearby who can call for help or assist in an emergency significantly improves your safety.
Disconnect the battery negative terminal before performing electrical work, and never start the engine or shift the transmission while the vehicle is on jack stands unless the service procedure specifically requires it. Movement from engine torque or accidental gear engagement can shift the vehicle off the stands.
Electric Vehicle Precautions
Electric and hybrid vehicles present additional hazards due to high-voltage components and heavy battery packs. Never touch orange high-voltage cables or attempt to open high-voltage battery enclosures. Consult the service information for your specific EV or hybrid to identify high-voltage components and safe support points before lifting.
Battery pack weight distribution differs significantly from conventional vehicles, affecting balance and required stand capacity. Verify that your jack stands are rated for the vehicle’s full curb weight including the battery pack.
Inspecting and Maintaining Your Jack Stands
Clean your jack stands after each use to remove dirt, oil, and debris that can hide cracks or corrosion. Store stands in a dry location to prevent rust, and apply a light coat of oil to bare metal surfaces and moving parts.
Check locking pins, ratchet teeth, and adjustment mechanisms regularly for wear, and replace worn or damaged components before using the stands again. Even high-quality stands have a service life and should be replaced if they show significant wear, damage, or have been subjected to impact or overloading.
Working Safely Under Your Vehicle
Jack stands are an essential tool for safe vehicle maintenance and repair, but they require careful selection, proper positioning, and strict adherence to safety procedures. By choosing stands with adequate weight capacity, placing them at the correct support points, following the proper lifting sequence, and verifying stability before you begin work, you can perform underneath maintenance and repairs safely.
Always consult your owner’s manual for vehicle-specific jacking and support points, inspect your equipment before every use, work on a level surface with wheel chocks in place, and never take shortcuts that compromise your safety. If you have any doubt about the correct procedure for your specific vehicle or the adequacy of your equipment for a particular job, seek guidance from a qualified professional before proceeding.
Continue learning about vehicle care and safety through additional Autos and Vehicles articles covering maintenance, repairs, and ownership topics.